Capturing deep-sea life on camera

19 December 2008

British scientists have filmed shoals of fish deeper than ever before. Previously unseen footage and the cutting-edge camera that captured it was on display in the Antenna gallery from 29 to 30 December 2008. Antenna dives in to find out more...

The dark line on the right of this satellite photo is the Japan Trench, where the Oceanlab team made their deepest marine movies.

Image: NOAA

Snailfish search for tiny shrimp-like creatures to eat by using their vibration sensors in the darkness of the ocean floor.

Image: Oceanlab

During their filming over the last few months, at nearly 5 miles down, scientists from Aberdeen University's Oceanlab captured a shoal of ghostly snailfish fighting over food.

'Any deep-sea biologist would feel extremely lucky if they saw, let alone filmed, a single fish at this depth. So when I watched our film from the Japan Trench showing an incredible number of fish actively swimming around, my blood started to circulate in reverse!' Toyo Fujii, deep-sea biologist

Toyo Fujii, deep-sea biologist, Oceanlab.

Image: Oceanlab

To film so much animal activity, so far below the surface, was a world-first. But how did the kit withstand the enormous pressure at the very bottom of ocean trenches?

Firstly, Oceanlab's camera was safely protected inside a stainless steel case. Without it the immense pressure of the water would have crushed it. The biggest challenge was finding a transparent material tough enough for the lens...

The camera sits safely inside the strong steel cylinder - it can withstand pressure equal to 1600 elephants standing on the roof of a Mini!

Image: Oceanlab

The engineers tested different materials inhigh-pressure chambers. Acrylic plastic deformed too easily, and glass of the right shape and thickness was well out of the team's price range. Surprisingly, it was the precious stone sapphire that made the cut.

'Sapphire is very strong and making a thin disc of this is actually cheaper than making a glass hemisphere,' says Alan Jamieson, lead designer of the kit. 'It's also better than glass as a camera lens because it can be made flatter and polished.'

Alan Jamieson, marine engineer, Oceanlab.

Image: Oceanlab

The team are keen to explore even greater depths in the future. They're planning to capture more footage and gather samples in other ocean trenches. Ultimately, they hope that their work will explain more about mysterious deep-sea ecosystems and help these areas be conserved.

Deep-dwelling creatures brought back to the surface will be used to piece together a better understanding of deep ocean habitats.